Key: Left -- Game Sprite; Right -- Recolored
[DISCLAIMER] I saved the picture as an optimized GIF, so Medicham looks like crap because it's speckled. Both Medichams got speckled because GIFs can only support a maximum amount of colors equal to 256, and the picture had a color amount slightly above that. I'll try to save it as a .PNG next time so it won't speckle any Pokemon.
The above shows how the Pokemon should really look according to the colors Sugimori used in thier respective official art. I think the most notable improvement is Rhyperior.
Rhyperior has always seemed horrendous to me with the extremely vibrant orange and plain gray, but Sugimori's art made him look amazing. Rhyperior basically started my recoloring on some Pokemon. On some Pokemon you may not notice a difference, and I only recolored them because my sister wanted me to recolor them. The old Medicham is almost exactly right to the Sugimori colors.